In the past, vibrating screen machines are normally made of a box-like structure mounted on flexible springs and contain one or multiple layers of screen mesh to sort granular materials. The different sized openings in the mesh allow sizing of materials according to the size of these openings. The box structure usually contains an eccentric weighted shaft that shakes the box and its screen mesh to agitate and separate the granular materials fed into the top of the machine. The speed at which the eccentric shaft spins is dependent on the type of screen process. Usually a higher speed is desired when sorting smaller granular materials, while slower speeds are desired for sorting coarse materials. A v-belt drive is commonly used to convert the speed of the driving motor to the desired speed of the screen shaft. Since the machine shakes from action of the eccentric weighted shaft, a flexible means of transferring power to the shaft is required to transfer power from the stationary driving motor which is necessarily located outside of the box like structure. Normally, this is accomplished using v-belts from the pulley of the motor to a pulley on the screen shaft. Either the motor is mounted on a pivoting base that allows the motor shaft to move with the screen shaft to maintain tension, or a belt tensioning idler is used to maintain belt tension between the driven pulley and the drive pulley. Many of these systems have performed well in the past. However, the pivot base method and tensioning idler method are both susceptible to belt slip and belt jump, especially when the screen is surging during startup and shutdown. Both of these also perform poorly if there is an attempt to decelerate the screen with the motor or a brake on the motor.
Also, the drive belts and motor are normally required to be removed to allow repositioning of the motor to minimize travel dimensions of the screen machine.
Consequently, there exists a need for a vibrating screen which allows the connection between the motor and the eccentric weighted shaft to remain in place during operation, transporting the screen and the process of converting from operational mode to transport mode.